Diagnostic testing throughout the world is currently carried out using a variety of different specimen types including whole blood, serum, oral fluid, plasma, cerebrospinal fluid and others. Testing for diseases under laboratory conditions typically involves use of a blood serum specimen obtained by removing the blood cells from an intravenous blood sample by centrifugation. The serum sample so obtained is then tested under laboratory conditions using one of a number of methodologies, such as Enzyme Linked Immuno Sorbent Assay (ELISA), Immunofluorescence (IFA), Latex Agglutination (LA), or any of a number of automated instrument platforms employing chemiluminescence, fluorescence or other sensitive technologies.
One such device for diagnostic testing employs a membrane having a receptor (e.g., an antibody) physically attached to its surface, wherein upon application of a sample, a piston means creates a region of reduced pressure thereby drawing analytes present in the sample through the membrane into a means for absorbing liquid. In this regard, an analyte which specifically binds to the receptor is readily detected. See, e.g., U.S. Pat. No. 4,797,260 and U.S. Pat. No. 5,137,691, incorporated herein by reference in their entireties.
Although serum testing under laboratory conditions has traditionally constituted the technique of choice, there is now a growing trend to move testing closer to the patient so that a patient sample is processed and analyzed more rapidly, often while the patient is still in attendance. The recent advance known as “near-patient” or “point-of-care” testing has caused a shift in the way testing is done.
In contrast to conventional testing, which requires a waiting period of anywhere from several hours to weeks, during which the specimens are transported to a centralized laboratory, processed, and results sent to the physician, point-of-care (POC) testing offers the advantage of giving the physician and/or the patient immediate results. POC testing is particularly advantageous in rural locals which may only have one centralized laboratory or countries with limited resources, wherein centralized laboratories do not exist.
In addition to human patient care, there are a variety of other applications for immediate testing capabilities, including veterinary applications, detection of bioterrorism agents, contaminant detection in quality control and environmental sources, and food safety.
While conventional benchtop testing devices such as TARGET ANALYZER (Target System Diagnostics) are known in the art, such devices are not adaptable to a point-of-care setting and require advanced training to read and interpret results. Needed is a portable handheld apparatus for providing a plurality of measurements and data analysis tools for diagnostic, environmental and quality control applications. Moreover, such a device preferably also contains easy turn-key test calibration. The present invention meets this need in the art.